R8247 and Elink

[NickL1982]

Dear all,

I live abroad ( where there are no model railway shops) and am keen to continue a childhood hobby. As everything needs to be shipped out, im keen to try and get all the equipment in one go ( as best as i can). I will use the Hornby Railmaster ( through a laptop) and Elink ( on an N guage layout, with the bigger transformer) but just have a few questions regarding how it works. Please forgive my ignorance!

1) Using the Elink, do I need the decoder, R8247 for example, and if so how do they work together?
2) My layout will have alot of points, is the deocoder or elink limited to only 4 points etc to change through the laptop, or can it communicate with many?
3) wiring, assuming the track has no breaks in it, does the Elink/decoder attach to one point on the layout and provide power to the whole system?

 

Thats it for just now, thank you all for taking the time and your assistance!

 

rgds

[Chrissaf]

EDIT: After writing this long reply. I then noticed that you intend to build a N Gauge track layout. The R8232 DCC point clips and the standard Hornby track power clips, including the ones supplied with the R8247 Accessory Decoders are meant for Hornby branded OO gauge track. All the principles outlined in my answers are all still applicable, but obviously the track power connectors used will be the ones recommended by your N gauge track manufacturer. The recommendations for the BUS implementation and the recommendation to directly connect the R8247s to the eLink track power still stand as written.

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1) Using the eLink, do I need the decoder, R8247 for example, and if so how do they work together?

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The R8247 is an 'Accessory Decoder'. You only need R8247 decoder(s) if you want to use DCC commands to operate points using Solenoid point motors. Other brands of Accessory Decoder will work with the eLink as well. Most other brands are what they call 'Self Learning' decoders and they can be easier to set up and configure than the 'rather long in the tooth' R8247. Some other brands also have inbuilt contact switches that can be used to provide enhanced functions such as for example synchronised switching of LED signals and/or manual over-ride switches that allow the point to be operated either by DCC commands from RailMaster OR manually by throwing switches or pressing physical buttons.

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Focusing on the R8247 to answer your question. The R8247 'brand new' comes with a track power clip. The R8247 clips to the track to listen to the digital DCC data being transmitted by the RailMaster / eLink controller on the track rails....see first image below. Each R8247 port has a sequentially numbered DCC numerical address. Say for example R8247 #1 has its ports numbered 1 to 4, then R8247 #2 has its ports numbered 5 to 8 and so on. The ports on the R8247 have three terminals for wiring to 3 wire Solenoid point motors. Two wire point motors are not supported by the R8247 unless a 3 wire to 2 wire adaptor is added to each port output (these adaptors are not made by Hornby but are made by 'DCC Concepts'). If you are not going to use Solenoid technology point motors. Then you need to use a non Hornby Accessory Decoder brand that supports the point motor technology you want to deploy.

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In RailMaster you create a track plan. that represents a logical representation of your layout. Each point placed on the track plan is configured in the software (by you the user) with the DCC address for that particular point. Thus, clicking the point on the track plan makes RailMaster send the appropriate software commands embedded within the DCC Data signal sent to the track. All the R8247s are listening to the track signal and detect any commands that are specifically addressed to them and ignore all others. When the appropriate R8247 hears its own address being transmitted in the track DCC data signal, it performs the action that the command is requesting i.e operate the point.

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Personally, I don't like using the Hornby track clips used by the R8247. They are a fault liability. I much prefer to hard wire the R8247s directly in parallel to the track output of the DCC controller. In this case the eLink 'Track A& B' output......see image below.

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2) My layout will have a lot of points, is the decoder or eLink limited to only 4 points etc to change through the laptop, or can it communicate with many?

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RailMaster and eLink is able to communicate with up to 2,048 DCC Accessory Addresses. This equates to a theoretical maximum of 512 x R8247s. However with that many R8247s you would need to split the R8247s into a large number of blocks of smaller numbers and power them via DCC Boosters. Booster design is a completely different 'ball game' and something to be discussed on another day if it becomes necessary.

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As I indicated in my answer to item 1) above, multiple R8247s can be connected to the DCC controller. In the case of the eLink, the factory provided 1 amp supply will be a limit on how many R8247s you can attach and still have power reserves for operating trains. If you have got a large number of points (say more than 16 or 20) then it might be prudent to upgrade the eLink 1 amp supply to the Hornby P9300 4 amp power supply. Each installed R8247 draws about 20mA standing current when idle with a brief pulse peaking at 200mA when a point is operated. Thus the idle current draw on the 1 amp power supply is relatively low for most average sized layouts.

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3) Wiring, assuming the track has no breaks in it, does the eLink & decoder attach to one location on the layout and provide power to the whole system?

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The decoder connectivity was discussed in my item 1) answer.

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Potentially you can operate a DCC layout with just a single power connection to the track from the DCC Controller [eLink]. To do so would require (assuming that Hornby track products are being used) that all the points be fitted with R8232 DCC point clips.Hornby points act as electrical switches to route power into the route that they are switched to. This is fine (and desirable) for DC Analogue controlled layouts, but DCC ideally needs the whole layout, main track plus sidings to be permanently live, hence Hornby's solution using R8232 DCC point clips

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A single power connection is fine for small layouts with a reasonably small number of points. Initially, if using all brand new track products, the layout is likely to work without issue. But over time, the reliability of the R8232 DCC clips and the metal track joiners can degrade and start to create power distribution issues. Reports have been made on the forum of R8232 clips glowing red hot and melting the plastic of the points.

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On larger layouts with many points it is by far more reliable to implement a DCC BUS system and eliminate the longer term reliability issues previously mentioned. In a BUS system, a thick pair of wires (typically 32/0.2mm) run around under the layout baseboard loosely following the routes of the track. Thinner dropper (typically 7/0.2mm) wires then solder to the outside rails of the track in strategic places and then pass through the baseboard to connect to the underneath thicker BUS wires. It is the thicker BUS wire pair that connect to the 'Track A&B' output of the eLink, negating the need for the supplied Hornby track clip (another fault liability) to be used.

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There is no 'hard & fast' rule for the number of 'droppers' used. Some just put in the minimum needed to eliminate dead track spots (because the DCC R8232 point clips are now not used). Others (and I fall into that camp) put droppers on every single individual track piece so that the metal track joiners are totally relegated to just providing physical track rail joining and are therefore not reliant for the electrical power distribution throughout the layout.

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32/0.2mm = 32 strands of 0.2mm diameter wire in a common insulation sheath

7/0.2mm = 7 strands of 0.2mm diameter wire in a common insulation sheath.

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TIP: I write long posts. If you intend to write a reply, it would be appreciated if you didn't use the 'White Arrow in Blue Box' button. This is not a 'Reply to this post button. It is best to write any reply you want to make in the 'Reply Text Box' at the very bottom of the page and click the Green 'Reply' button.

 

Particularly as my reply includes images. If you use the blue button, any reply you write, may be held back for image approval. Even though they are already previously published images.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

 

[NickL1982]

Dear Chris, thank you very much for your in depth reply and the information. 

very helpful and informative and food for thought!

[Chrissaf]

Before you try installing and setting up RailMaster...I suggest you review my 'How To' posts on this forum and also the external RailMaster 'help site'. Being forwarned with the potential installation issues beforehand may save you some grief in the long run.

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External Help Site

https://octaviancs.com/railmaster/rm.php

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My 'How To' posts:

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Installing eLink with RM for the 1st time issues.

https://www.hornby.com/uk-en/forum/installing-elink-with-rm-for-the-1st-time-issues/?p=1/#post-313903

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eLink not recognised – checking COM port numbers & .INI entries

https://www.hornby.com/uk-en/forum/train-will-not-run-on-elink-plus-other-issues/?p=1

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** alternative version to the above.

https://www.hornby.com/uk-en/forum/adding-the-hornby-r8213-dcc-select-controller/?p=1

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Note that in the posts above, references are made to eLink and Elite for the controller & drivers and Windows 8 and/or Windows 10 for the RailMaster installation. The content of the posts are, in the main, common to all the different controller / Windows combinations. Specific products were mentioned in the posts to reflect what the original question raised related to.

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Once Railmaster is communicating error free with the controller, then these posts will help with setting RailMaster up with your loco fleet.

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Full description of the ‘Locomotive Settings’ screen in detail.

https://www.hornby.com/uk-en/forum/changing-cruise-and-shunt-speeds/?p=1

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Setting up Flying Scotsman TTS Sound Functions.

http://www.hornby.com/uk-en/forum/how-to-set-up-default-sound-functions-on-scotsman-r3284tts/?p=1

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Expanding the large throttle to see all function buttons.

https://www.hornby.com/uk-en/forum/sound-functions-in-rm/?p=1

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“on/off” function button labels

https://www.hornby.com/uk-en/forum/post/view/topic_id/19619/?p=2

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Then these will help with creating a 'Track Plan' and operating points using the R8247 Accessory Decoder.

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Adding & Configuring Points in RM Track Plan (R8247)

https://www.hornby.com/uk-en/forum/railmaster-decoder/?p=1

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Blue point position indicators missing in track plan.

https://www.hornby.com/uk-en/forum/points-direction-missing/?p=1

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[NickL1982]

Ok thank you. So in one of the diagrams you had the accessory decoders hard wired to the link from the elink to the track.  Is this hard wired joint done by soldering together?

 

secondly, rather than running alot of power through clips onto the track, could you use soldering which would be a stronger connection?

 

thirdly, with the bus wire system, how are the bus wires connected to the power source?

[Chrissaf]

Is this hard wired joint done by soldering together?

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It could be, but you could also use electrical screw down terminal strips. Any method of connecting wires that is convenient for you is OK. There is no 'hard n fast' rule on this.

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could you use soldering which would be a stronger connection?

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Do not under any circumstances solder the metal track joining fishplates to the rails. The track joints need to be able to expand and contract with changing temperatures.

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If you mean soldering the main power wires from the controller to the track, then yes.....soldering wires direct to track rails is a much better option than using the Hornby track power clips.

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But note this. If you deploy the BUS solution (your third question below). The BUS solution actually replaces the main controller to track power connection. The BUS solution IS the main track power connection.

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how are the bus wires connected to the power source?

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Assuming the Hornby eLink DCC controller, these have press down lever connection terminals. The BUS is just a pair of wires, just like the normal track connector wires. Thus you just bare about 12mm of wire at the ends of the BUS wires and clamp them under the controller press terminals exactly the same as you would if you were using the normal track connector wires.

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I don't particularly want to complicate matters, but this (schematic below) is my preferred BUS arrangement and the one I have implemented on my own layout. The 'terminators' (snubbers) are beneficial as they offer the Loco and Accessory Decoders a high level of protection from being corrupted by transient 'short circuits'. The 'droppers' in this schematic are the connections to the actual track at a number of strategic locations (main loops and sidings). The droppers can also double up as the DCC track connections to your R8247 Accessory Decoders.

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The implementation of a T-BUS with snubbers BUS design is a 'Marmite' thing. Not everyone shares my view on BUS design and I do acknowledge that on a small / medium sized layout it is over-kill. But in my view it is still 'best engineering practice'. Since implementing this BUS design on my own layout I have never experienced a loss of decoder configuration or experienced any decoder damage due to 'short circuits'. I cannot claim to have had the same experience before I fitted the terminating snubbers.

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To read more on 'Snubber' theory follow this link:

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Note that each terminator draws about 100mA of current from your eLink power supply and will run very warm to the touch (the heat is normal). Because of the current they draw, then the eLink 1 amp power supply upgrade to 4 amps is recommended if the terminators are deployed.

 

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[NickL1982]

Ok Chris thank you.

So, using the bus wire and elink, would i have 4 wires coming from the elink ? 2 for power ( track A-B) and 2 for the actual digital signals (prog)

 

also, I would use the hornby 4A transformer plugged into the elink as the power supply.

have i got the hang of it? 

[Chrissaf]

The two wires from the track (my BUS wires in my drawing) would go to the 'TRACK A&B' output of the eLink. This connection transports the DCC Digital commands as well as the track power to the track and to all the decoders, whether they be physically located in a loco or stand alone as in an Accessory decoder.

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The eLink 'PROG A&B' output terminals DO NOT UNDER ANY CIRCUMSTANCE connect to your main track. To do so will instantly damage the 'PROG A&B' output of the eLink. The 'PROG A&B' output of the eLink terminate on a completely separate physical piece of track and is used specifically for programming the CVs in the loco decoders before they are operated on the main track.

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This is my programming track piece as an example [Mounting carved out of a length of 2 x 2 timber].

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The Hornby P9300 4 amp power supply is the official Hornby 4 amp power supply upgrade for the eLink. The P9300 is the standard power supply shipped with the Elite and the R8239 booster (now obsolete). The P9300 is also the official upgrade power supply for the Select too.

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[NickL1982]

Ok thats great. Yes i did wonder if the bus wire could also carry the digital signal.  So all in all, it seems soldering, using the bus system seems the best solution offering longevity. 

further to your diagram, the R8247 decoder is hardwired to the bus wire from elink to the track? those two wires from the elink carry everything, hence the reason for using a strong wire. 

thanks again, much appreciated

[NickL1982]

Just finally Chris, the RM and elink cannot change points on its own, it requires the r8247 to be connected for this function? 

[Chrissaf]

Yes.....or another non Hornby branded Accessory Decoder.

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Some point motors (DCC Concepts Cobalt iP Digitals for example) have the Accessory Decoder function directly built into the point motor itself. In theory, as long as the kit from different manufacturers all comply with the American NMRA (National Model Railway Association) DCC S-9 Electrical Standard, then they should all work seamlessly together.

[96RAF]

Just to put this bus concept on a level playing field.

 

The track conducts power rail to rail from the controller via the track connectors. This can be unreliable If the rail joiners become loose.

 

A bus merely replicates the track system by way of hard wiring of each track piece to a pair of wires connected to the controller, rather than the controller being connected to the track.

 

The advantage of a bus being that the continuity between controller and each track piece is assured.

 

When we digress into track and point bus, we are simply separating the feed from the controller to the track and the points but for protection against a track short affecting the points we can introduce a circuit breaker into each sub-circuit. Thus if a loco derails due to a bad point selection and shorts the track circuit we maintain control of the point to be able to correct the problem.

[NickL1982]

Forgot to ask before, the points, do they connect to the main bus wire with their own wires, or do they take their signals from the previous soldering of the dropper wires to the track?

[Chrissaf]

Please re-read my reply posted on 8th Feb @ 11:54 (Page 1 of this thread)

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In it I wrote:

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So if you only put in a minimal strategic number of droppers, then the lengths of tracks with droppers attached will get their power via the droppers. Lengths of tracks (including points) that do not have their own dedicated droppers will get their power from the adjacent track pieces via the metal track joiners. As I said before, over-time the metal track joiners can loosen and become tarnished (oxidised). This has the potential to make power on some sections of the layout intermittent. My preferred solution is to fit droppers to each and every track piece (including points). But I stress that this is just my own personal choice as it is a lot of extra work.

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Regardless of how many droppers you fit. If nothing else do this. As you attach each dropper pair to the rails and BUS, check the main BUS wires for a 'short circuit'. Preferably with a multi-meter on Ohms (Resistance) scale. If any dropper pair is attached with the wires reversed, then you will get a 'short'. If you don't check for 'shorts' as you progress the wiring installation, then trying to find a 'short' later (after the horse has bolted) is extremely difficult and onerous.

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So far you have not provided a sketch of your proposed track plan. Some layout designs create 'short circuits' because the design includes a 'reverse loop'. I define a 'reverse loop' as being any route that a loco can take throughout the layout where it arrives back at the starting point but facing in the other direction. This includes turntables. If you were to post a schematic drawing of your proposed layout design, than a 'reverse loop' analysis could be done for you. Plus suggestions as to where the main strategic BUS droppers need attachment.

 

[NickL1982]

Dont laugh!! This is a rough idea what i have in mind. I have a fair bit of space, so will try and make the most of it. It is subject to change. But roughly this is my idea. I also had an idea of running the bus wire in a wave pattern under the board, thus it can connect to most sections of the track without having extended dropper wires. I understand its alot more work, but i would agree that this promotes the best soloution with a layout.

 

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[NickL1982]

I did try and post a picture of the track plan i want to use but it did not work, i will try again.

the track will be approx 3m by 2m with 2 main loops that branch out to form 4-5 parallel tracks on the long sides of the layout. Il also add a siding when im confident with what im doing.

i will use the bus wire, and try and connect the dropper wires every few peices of track or so.

ive seen theres lots of posts/videos on soldering.

i think youve answered all questions so far, thank you. Anymore that come to mind il post. 

[Chrissaf]

Posting an image is TIP 8 in my TIPs page.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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Image will be held back for admin approval for which there is currently a possible delay due to admin availability issues.

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Here is my thread on 'How to Solder'.

https://www.hornby.com/uk-en/forum/how-to-solder-for-model-railways/?p=1/

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[Chrissaf]

I can confirm that there are no reverse loops in that proposed track plan**. Now that the track plan is visible, a DCC BUS solution is definitely the optimum way of powering it, and the correct engineering decision to make.

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Note** The TurnTable? may possibly generate a 'reverse loop short circuit' if it is not a DCC friendly one. The Hornby R070 TT is not DCC friendly out of the box and needs DCC modification.

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Either put droppers on each and every track piece (option 1 for maximum long term reliability) OR strategically put droppers on the 'TOE' end of each and every point plus on 'open ended' sidings, as the 'strategic only' locations option 2.

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Note that the 'TOE' end of a point is the 'common end', not the divergent routes end of the point which do confusingly look more like toes.

[96RAF]

To get more trackage in your fiddle yard sidings at the left hand side you may wish to rework the points layout same as you have at the right hand side....

Top - as is

Bottom - suggested

To do so simply swap RH points at one end for LH points from other end and vice-versa.

/media/tinymce_upload/c0362dbd3a6c3432bd306019ff179d17.png

Image originally posted by Howard (HBMan) if I remember correctly.

[NickL1982]

Dear both,

 

thank you very much. I have a lot of good info to start with and as soon as the r8247 is released ( which should be anytime?), i will start.

im sure more questions will pop up  as i begin. 

thank you.

[NickL1982]

Hello again,

 

i just wanted to clarify the types of points i should use, electrofrog or insulfrog? I have read the differences but can you reccomend which youd use for my layout?

 

additionally, the points require no extra equipment to change them, only a connection ( as discussed) to the bus wire and thus the elink and accessory decoder?

[Chrissaf]

Your layout drawing on page 2 of this thread is a very extensive and ambitious layout design. Your layout plan shows that the design is based on Peco ST track. Peco SL Electrofrog points use a completely different geometry to Peco ST Insulfrogs, so if you go down the Electrofrog route you will have to bin your proposed design and start all over again, and due to the difference in geometry might have to be less ambitious.

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...additionally, the points require no extra equipment to change them, only a connection ( as discussed) to the bus wire and thus the eLink and accessory decoder?

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Not quite true. The Accessory Decoder only converts the Digital DCC command signal and power into DC Analogue control wires. You then also need an electrical point operating motor to attach to the points. One per point. The point motors convert the DC Analogue electrical currents from the Accessory Decoders into mechanical force to physically operate the point.

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Since your propsed track is Peco ST.

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The Peco point motors that are compatible with the R8247 are:

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Peco PL10E (mounts under the baseboard on an additional  PL09 mounting plate)

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Peco PL 11 (mounts on the surface next to the point, can be an issue where multiple points are in close proximity....not enough mounting space).

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Then there are integrated point motors that integrate the function of the Accessory Decoder and the function of the point motor into one single physical package negating the need for the R8247s. One such integrated point motor as an example is the DCC Concepts - Cobalt iP Digital. Note, Hornby do not make or sell integrated point motors.

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Mounts under the baseboard.

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Then as your proposed track is Peco, you then might want to consider using Peco's 'Smart Switch' system. The complete DCC version of the 'Smart Switch' system consists of a DCC decoder interface board - purchased separately on a 'one per control board' basis (negating the need for Hornby R8247 decoders), plus point control boards, then the control boards operate point motors based upon Servos (four included in the kit version). The system can be expanded to accomodate large numbers of points on the layout. As this system is not a Hornby product you will need to do your own research on this product on the Peco website.

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[NickL1982]

Thank you. So in the above, the peco switches are stand alone, they are not connected to the laptop running the elink, and further negates the need for the decoders? As the laptop only controls the rolling stock?

[Chrissaf]

INCORRECT.

 

With any and all DCC point operating solutions, they HAVE to connect ultimately to the eLink via an Accessory Decoder of some description IF you want to control them using DCC commands sent from the RailMaster controller system.

 

I was just pointing out in the previous replies that some point operating products include an integrated Accessory Decoder built into them. The DCC Accessory Decoder is still there, it just isn't a separate box. The PECO Smart Switch system also has a DCC Accessory Decoder, but it is optional.

 

You are however at liberty to operate your points completely independently from any DCC command system by whatever means you choose and use the DCC command system to just control the locos on their own. But if you do that, then you will lose the ability to click point icons on the RailMaster screen to operate points. Which rather negates the benefits of using RailMaster software control to operate your layout.

 

Just an observational comment, but there seems to be an 8 month gap in this dialogue timeline.

[NickL1982]

Many thanks for the clarification. The 8 month gap was due to the impact of covid on my employment and making plans going forward. The gap by no means implies a loss of interest, more a changing of my priorities.